1. Technical Field
The present invention relates to a light source device and a projector.
2. Related Art
In the related art, a discharge emission light source device causing discharge emission between a pair of electrodes has frequently been used as a light source device in a projector. Further, as such a projector, there has been also proposed a dual-lamp projector provided with two light source devices in order for improving the brightness of the projected image (see, e.g., JP-A-2002-258248 (Document 1)).
Specifically, in the projector described in the Document 1, the two light source devices are disposed on the rear side, which is opposed to the position where a projection lens for projecting the image is disposed, inside an exterior housing forming an outer package, and is disposed so as to be opposed to each other around a combining prism. Further, luminous fluxs emitted from the two light source devices are combined in the combining prism, and then output along the direction in which the image is projected from the projection lens.
Incidentally, as the light source device, there is provided a light emitting tube having a substantially spherical light emitting section provided with a pair of electrodes disposed therein. When such a light emitting tube is lit, the temperature of an upper portion of the light emitting section becomes the highest, and the temperature of a lower portion thereof becomes the lowest. If the high temperature state of the upper portion of such a light emitting section continues, devitrification becomes apt to occur on the one hand, if the difference in temperature between the upper portion and the lower portion becomes large, blackening becomes apt to occur on the other hand, and thus the light emitting tube becomes apt to be deteriorated.
Therefore, in the related art, there has been adopted a technology of providing an air induction port to the upper portion of the light emitting tube to thereby send air to the upper portion of the light emitting section via the air induction port in a housing for housing the light emitting tube and a reflecting mirror.
Incidentally, in the dual-lamp projector described in the Document 1, it is preferable that the two light source devices are made to have the same structure so that a certain light source device can be used as either one of the two light source devices when taking the cost and usability into consideration.
However, in the dual-lamp projector described in the Document 1, in the case in which the two light source devices are made to have the same structure, and at the same time the technology described above and a structure of replacing the two light source devices described below are adopted, the problem described below arises inevitably.
As the replacing structure of the two light source devices, it is possible to adopt a structure for performing the replacement from, for example, a lateral side of the projector.
Specifically, a replacing lid is detachably attached to a sidewall of an exterior housing on the rear side thereof, and the two light source devices are taken out from the rear side to the outside of the exterior housing in the state of keeping the replacing lid detached from the exterior housing. Further, by attaching two new light source devices to the inside of the exterior housing from the rear side, respective connectors (hereinafter referred to as light source side connectors) provided to the respective light source devices are connected to respective connectors (hereinafter referred to as housing side connectors) provided to the inside of the exterior housing, thus forming the state (the state in which the light emitting tube can light) in which electrical power is supplied to the light emitting tube via the respective connectors.
Further, in the case of adopting the replacing structure, the light source device (hereinafter referred to as a first light source device) disposed on the right viewed from the projection side is required to have the light source side connector facing to the right in view from the forward side of the light emission. On the other hand, the light source device (hereinafter referred to as a second light source device) disposed on the left viewed from the projection side is required to have the light source side connector facing to the left in view from the forward side of the light emission.
Specifically, in the case of making the two light source devices have the same structure, by for example disposing the first light source device and the second light source device so as to take postures vertically opposite to each other, it becomes possible to set the orientations of the light source side connectors to be the state described above in both of the light source devices.
However, in the case of adopting the technology described above, since the first light source device and the second light source device have the postures vertically opposite to each other, although the air induction port is located on the upper side in one of the light source devices, in the other of the light source devices the air induction port is located on the lower side.
In other words, although in the one of the light source devices the longer life of the light emitting tube can be achieved by sending the air to the upper portion of the light emitting section via the air induction port, the air is sent to the lower portion of the light emitting section via the air induction port in the other of the light source devices, and therefore, the longer life of the light emitting tube is not achievable.
Under the circumstances described above, there has been demanded a technology capable of achieving the longer life of the light emitting tubes in the respective light source devices even in the case in which the two light source devices having the same structure are incorporated in a projector, and at the same time, there is adopted the structure of replacing each of the light source devices from a lateral side of the projector.